Here's a nuthatch of mine, done with a lowly 70-200 f/4 on my crop camera.

thanks no i wish a 600mm but out of my budgetits canons 400mm f5.6L the trick is getting closerIs yours an American Nuthatch?

You're quite welcome. Cool, I've rented that lens, I liked it...congrats on getting stellar results with it! Alas I chose to buy a softer Sigma zoom. So far I like it considering the price (especially the color rendition), but I've only used it for an hour. Here's an admittedly compromised shot below, done today through a glass window (the storms brought wind gusts to 40 mph today!) ISO 2000, 1/200 with OS on, f/7.1, 400mm, 50% crop, then reduced from 2000 pixel width to 770.

I was told that other bird was a "brown headed nuthatch". This one is quite small, not much bigger than a hummingbird. I'm the opposite of a bird expert. I just know there aren't much variety of the small birds here...or if there are more, they don't make themselves conspicuous. I'm not much into using blinds or camping out in the mountains for a week to try to see the rarer species...especially when there are so many other people out there doing such great work already (most of them not getting paid for it).

Because of this Vultures high contrast and lack of color it is typically a difficult bird to properly expose while in flight. Finally this one turned out quite well. The ambient light at this very moment was just ideal as well as the bird's altitude for a 400mm on a full frame. It's tricky as you have to overexpose by 1-2 full stops to get the under carriage but then that kills the white beak..even highlight recovery is useless at that point.Rev

Because of this Vultures high contrast and lack of color it is typically a difficult bird to properly expose while in flight. Finally this one turned out quite well. The ambient light at this very moment was just ideal as well as the bird's altitude for a 400mm on a full frame. It's tricky as you have to overexpose by 1-2 full stops to get the under carriage but then that kills the white beak..even highlight recovery is useless at that point.Rev

Rev, I couldn't agree more. Very difficult to get a good capture of a Vulture. I've only gotten one Vulture image that I really liked myself, it showed his topside rather than underside, but I felt like it caught the beauty of the beast... I'll post it...

Here's a group portrait. The birds are Great Tailed Grackles and I made this photograph this afternoon at Sweetwater Wetlands, a man-made marsh near Tucson, Az. I call this image "Walpurgisnacht". Think of witches on broomsticks. Canon 5D iii, EF 100-400 f4-5.6 L. Substantial cropping, some brightening of image, no sharpening, lighting "as is."